Jodi Axelson Dept Geography, University of Victoria Ecological impacts of the Mountain Pine Beetle on the Foothills of Alberta René Alfaro, Brad Hawkes, Lara vanAkker and Bill Riel Pacific Forestry Centre, Victoria, BC, Canada Jodi Axelson Dept Geography, University of Victoria Ian Cameron Azura Informetrics

Contents Introduction Disturbances: drivers of ecosystem change Need for establishing baselines Need for forecasting growth and yield and flow of ecosystem services following MPB Work in the BC and Alberta Forest transformation by MPB actual and stand simulations Knowledge gaps and opportunities Conclusions

Ecology of lodgepole pine: a fire regenerated species

Life after fire

The mountain pine beetle Forest management, climate change Fire suppression and selective harvesting for species other than pine during previous century, created large forests of pine Beetle survival has improved over much of western Canada during recent decades due to global warming, allowing populations to invade areas formerly unsuitable for MPB

Probable range of the MPB A very plastic insect= High potential for invasion US Distribution from McCambridge and Trostle 1970 Canada Distribution: from Alberta and BC sources

Largest pine beetle outbreaks in BC and Alberta in recent history Aerial surveys begin History of beetle outbreaks in BC

BC Montana Border 31 years later Ecological and timber impacts 1980 1985 2011 BC Montana Border 31 years later

The Cariboo-Chilcotin Plateau plots Established 1987, remeasured in 2001 and 2008 3 biogeoclimatic zones Mixed-severity fire regime Stands dominated by Pl

East Slopes sites New range Historic range

20 Years after MPB in Waterton National Park Thank you to organizers and Cyndi Smith from Waterton Lakes NP for asking me to speak at this public science forum. As part of a larger project in BC looking at how lodgepole pine stands change after a MPB outbreak, 25 MPB impact plots, established by Ben Moody from our CFS Alberta research centre in Edmonton in the early 80s, were re-measured in 2003, 20 years later. A big thanks to Rob Watt, Park Warden, Waterton Lakes NP who assisted Ben and his crew with those early plots and decided to make copies of the field data forms. This copied forms turned out to be the only complete set of them that existed in 2003. Also thanks to Leo Unger, a FIDS ranger with us in Victoria that discovered these plots existed and recommended we try to find them. Also for Rob taking landscape photos during the outbreak and then again in 2003. Mountain pine beetle is a natural part of the forest ecology of Waterton Lakes NP. This short presentation is about how the forest have changed over those 20 years.

Waterton Lakes NP, Red Rock Canyon – 1982 and 2008

Methodology: Establishing beetle disturbance baselines Past distribution of MPB outbreaks and return interval Understanding impacts. Timber and ecosystem Dating regen. cohorts Dating coarse woody debris Dating canopy layers

Disturbance history in “even” and uneven aged stands

Results: Stand development after beetle MPB is a natural thinning agent Promotes increased growth among the surviving trees Allows for the establishment of seedlings in understory Creates coarse woody debris

History of the canopy layers of an “even-aged” lp stand Logan Lake, Kamloops Axelson J., Alfaro, R., and Hawkes, B. 2009.

Beetle and stand dynamics: Bull Mtn Beetle and stand dynamics: Bull Mtn. Study Heath and Alfaro 1990 (re-surveyed in 2001) Overstory Understory Tree ring widths (mm)

Chilcotin: Growth release after 1970-80’s outbreak 1882-2001

Beetle history of in BC and Alberta

Bull Mountain 2001: Douglas-fir A 320 year old tree: outbreaks every 52 years (40 years for entire BC) Douglas-fir This diagram shows the lodgepole pine fire cycle . It illustrates the complexities of the many interrelationships involved. The two large arrows illustrate that seedling establishment and subsequent development of stand density, age structure, and composition depend, in part, on the type of fire that last occurred and the previous stand characteristics at the time of burning. The red highlighted areas illustrate that fire can influence seedling and stand development but the reverse also happens. An example would be a wildfire burning a mature lodgepole pine stand versus a very young stand. The result may be a dense pine stand with a lot of potential course woody debris from the fire-created snags or an open lodgepole pine stand with little or no coarse woody debris. During stand growth and development, the fuel and related fire potential undergo change, depending largely upon natural mortality and stage of succession. Other non-living and living agents can interact with fire disturbance such as windthrow, diseases such as root and stem rot, canker rusts, bark beetles (orange), insect defoliators, and mistletoe. Understanding the interactions of fire, beetles, and other agents is still somewhat limited and requires more study. We do know some of the effects of bark beetles and wildfire on forest succession but more study is needed.

Beetle creates advance regeneration

Beetle and stand dynamics From simple post-fire stand structure… To multiple cohort structure

Beetle creates coarse woody debris CWD from the 1970’s-80’s outbreak

Beetle creates coarse woody debris CWD from the 1930’s outbreak

Fire interactions Chilcotin Fire control implemented

Brad plays with fire

Resiliency of the Chilcotin Forest after two outbreaks

Resiliency of the Chilcotin Forest after two outbreaks Live pine in 2008 after 1970’s and 2000’s outbreak Density (stems/ha) Volume (m3/ha) Layer Mean SE Overstory (>7.0cm DBH) 413 84 27.9 5.3 Understory (<7.0cm DBH, taller than 1.5m) 1035 168 Regeneration (shorter than 1.5m) 4709 1429 Total 6157

3 cohorts Initial conditions 2008 AC3R3T125

2033 AC3R3T150

2041 (immediately prior to light outbreak) AC3R3T158PRE

2041 Light outbreak removes 30 % BA AC3R3T158

2058 New cohort is born AC3R3T175

2074 (immediately prior to outbreak) AC3R3T191PRE

2074 Massive outbreak kills 70% BA AC3R3T191

2083 AC3R3T200

2108 New cohort is born AC3R3T225

Results: Waterton National Park Pine is mostly down Forest dominated by shade tolerant

History of beetle at Waterton Outbreaks 1920’-1930’s 1970’6-1980’s

Overstorey Saplings Regeneration

Results: Waterton Marked decline in lodgepole pine density Increase in non-host species such as spruce and fir from 1981 to 2010 With the exception of stand 1, sapling and seedling densities have increased in all stands from 2002 to 2010 High degree of variability in stocking between stands Composition made up almost entirely of shade tolerant species

Conclusion: Stand dynamics cycle in BC

Historic habitat New habitat

Resiliency or Panarchy 101 Gunderson and Holling 2002 Conclusion Resiliency or Panarchy 101 Gunderson and Holling 2002

Resiliency

Resiliency

Resiliency 47

Transition to other ecosystems E.G. Transition to grassland E.G. Transition to Douglas-fir 48

Conclusions Stand-replacing fires initiate even-aged lp stands Reduced fire in 20th century: MPB directs stand dynamics MPB transform stands into multiple age cohort forests, initiated by repeated beetle thinning. Or transition to other stand types Long term impacts: alleviated by the presence of a sub-canopy, and advance regeneration layers which will form reasonably well stocked forests in the future.

Impacts on timber and ecosystem services Timber production is heavily impacted Ecological impacts or ecosystem services: If disturbance is part of cycle, business as usual In novel habitats: transition to different ecosystems Caveat: climate change will alter natural disturbance regimes.

Dendroctonus ponderosanegger “I’ll be back” http://cascadiascorecard.typepad.com/ Dendroctonus ponderosanegger

Questions?